Because it is a budren to maintain and LGPL 2.1 does not require
them, but only suggest them:
> To apply these terms, attach the following notices to the library.
> It is **safest** to attach them to the start of each source file
> to most effectively convey the exclusion of warranty; and each
> file **should** have at least the "copyright" line and a pointer
> to where the full notice is found.
https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html#SEC4
Because alignment was all broken and becaues it doesn't improve much
the code readability, but potentially create more complicated diff, we
prefer to unlaign all docblocks.
If $a or $b are not strings, you can get an error that fmod needs param 1 ($a) to be of type double.
MS Excel does not fall over when you insert an empty string in MOD, so I'm guessing PHPExcel should do the same?
```php
<?php
$array = array(
'str' => 'foo',
'num' => 12345,
'null' => NULL,
);
print intval(isset($array['null'])) . PHP_EOL;
print intval(array_key_exists($array['null'])) . PHP_EOL;
print intval(isset($array['num'])) . PHP_EOL;
print intval(array_key_exists($array['num'])) . PHP_EOL;
print intval(isset($array['str'])) . PHP_EOL;
print intval(array_key_exists($array['str'])) . PHP_EOL;
```
Only for this special case, you need array_key_exists(), else avoid it as it is
painfully slow and hurts your performance.
Signed-off-by: Roland Häder <roland@mxchange.org>
